Structure and Mechanism of Phosphoenolpyruvate Carboxykinase

INTRODUCTIONPhosphoenolpyruvate carboxykinase (ATP-oxaloacetate carboxylyase (transphosphorylating), EC 4.1.1.49, or for the GTP- or ITP-dependent enzyme, EC 4.1.1.32; PCK, 1The abbreviations used are: PCKphosphoenolpyruvate carboxykinaseOAAoxaloacetatePEPphosphoenolpyruvateP-loopphosphate-binding loop. also known widely as PEPCK) catalyzes the decarboxylation and mononucleotide-dependent phosphorylation of oxaloacetate to form phosphoenolpyruvate (Scheme 1; M2+ represents Mg2+ or Mn2+).This conversion is the first committed step of gluconeogenesis in Escherichia coli and is part of the gluconeogenic pathway in virtually all organisms. In bacteria, such as E. coli, PCK is utilized during gluconeogenic growth when sugar levels are low (1Goldie H. Sanwal B.D. J. Bacteriol. 1980; 141: 1115-1121Crossref PubMed Google Scholar).PCK is also an important enzyme in the glycolytic pathways of some organisms, such as Ascaris suum (2Christie D.A. Powell J.W. Stables J.N. Watt R.A. Mol. Biochem. Parasitol. 1987; 24: 125-130Crossref PubMed Scopus (12) Google Scholar) and Trypanosoma cruzi (3Cymeryng C. Cazzulo J.J. Cannata J.J. Mol. Biochem. Parasitol. 1995; 73: 91-101Crossref PubMed Scopus (24) Google Scholar), where it forms OAA from PEP, which in turn enters the citric acid cycle. In humans and other mammals, PCK is a central enzyme in carbohydrate metabolism, helping to regulate the blood glucose level. Gluconeogenic tissues, such as kidney and liver, convert lactate and other non-carbohydrate molecules to glucose, which in turn is released into the blood. The importance of PCK to carbohydrate metabolism in humans is such that it has been suggested as a potential drug target in the treatment of non-insulin-dependent diabetes mellitus (4Valera A. Pujol A. Pelegrin M. Bosch F. Proc. Natl. Acad. Sci. U. S. A. 1994; 91: 9151-9154Crossref PubMed Scopus (253) Google Scholar).PCKs have been traditionally classified according to nucleotide specificity, with the ATP-dependent enzymes found in bacteria, yeast, Trypanomastid parasites and plants, and GTP-dependent PCKs in a variety of other eukaryotes and mammals (5Utter M.F. Kolanbrander H.M. Enzyme (Basel). 1972; 6: 117-168Crossref Scopus (252) Google Scholar). There are both important differences and similarities between ATP- and GTP-dependent PCKs. With the exception of bacterial PCKs, which are monomeric (6Goldie H. Sanwal B.D. J. Biol. Chem. 1980; 255: 1399-1405Abstract Full Text PDF PubMed Google Scholar), most enzymes of the ATP-dependent class are multimeric, with two (7Urbina J.A. Arch. Biochem. Biophys. 1987; 258: 186-195Crossref PubMed Scopus (45) Google Scholar), four (8Tortora P. Hanozet G.M. Guerritore A. Anal. Biochem. 1985; 144: 179-185Crossref PubMed Scopus (35) Google Scholar, 9Walker R.P. Trevanion S.J. Leegood R.C. Planta. 1995; 196: 58-63Crossref Scopus (64) Google Scholar), or six (10Finnegan P.M. Burnell J.N. Plant Mol. Biol. 1995; 27: 365-376Crossref PubMed Scopus (27) Google Scholar) subunits per enzyme, while known members of the GTP-dependent class are exclusively monomeric. While enzymes of either the ATP- or GTP-dependent classes show significant (40-80%) amino acid sequence identity within their respective groups (11Linss J. Goldenberg S. Urbina J.A. Amazel L.M. Gene (Amst.). 1993; 136: 69-77Crossref PubMed Scopus (26) Google Scholar, 12Reymond P. Geourjon C. Roux B. Durand R. Fevre M. Gene (Amst.). 1992; 110: 57-63Crossref PubMed Scopus (29) Google Scholar), there is no significant overall sequence homology between the two classes of enzyme. Despite this lack of overall homology, both groups of PCKs contain similar NTP and oxaloacetate binding “consensus in their which similar in binding in this both GTP-dependent and ATP-dependent PCKs have been to C. S. E. Arch. Biochem. Biophys. PubMed Scopus Google Scholar, S. R. H. E. J. Chem. 1993; PubMed Scopus Google Scholar, S. H. E. 1995; PubMed Scopus Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar, PubMed Scopus Google Scholar), E. Biophys. 1987; PubMed Scopus Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar), and J. Biol. Chem. Full Text PDF PubMed Google Scholar, P. C. H. E. J. Chem. PubMed Scopus Google Scholar) or their The differences in nucleotide and between ATP- and GTP-dependent PCKs have to the that potential in Mol. Biochem. Parasitol. 1992; PubMed Scopus Google Scholar) and in Trypanomastid parasites such as cruzi (11Linss J. Goldenberg S. Urbina J.A. Amazel L.M. Gene (Amst.). 1993; 136: 69-77Crossref PubMed Scopus (26) Google from the of E. coli PCK A. H. J. Mol. Biol. PubMed Scopus Google Scholar, A. of E. coli Google Scholar), with A. U. H. Biol. PubMed Scopus Google Scholar), and the for the and of E. coli and other ATP- and GTP-dependent PCKs. also and for the GTP-dependent PCK of GTP-dependent PCK and have been Mol. Biol. 1994; of E. coli of E. coli PCK in M. C. H. J. Mol. Biol. PubMed Scopus Google Scholar) and to the and A. H. J. Mol. Biol. PubMed Scopus Google Scholar). The of the of E. coli PCK A. U. H. Biol. PubMed Scopus Google Scholar). other and E. coli PCK has an The is and of a and a or The two are a of in which the is is such that a central is either an of from the the of E. coli PCK with the C. J. Mol. Biol. 1993; PubMed Scopus Google Scholar) with a significant of overall of the E. coli PCK amino acid sequence with from other ATP- and suggested a most the R. H. H. J. Bacteriol. PubMed Google Scholar). have the of J. Biochem. 1994; PubMed Scopus Google Scholar) for the of within that with this the M. J. PubMed Scopus Google Scholar), the is the PCK the sequence forms a or to ATP- and M. A. Biochem. Sci. Full Text PDF PubMed Scopus Google Scholar). is within the and of the of the that it is in with from a variety of other J. Mol. Biol. PubMed Scopus Google Scholar), U. A. J. PubMed Scopus Google Scholar), and 1992; PubMed Scopus Google Scholar). Despite the within which the is found to for other this Biol. 1992; Scopus Google Scholar) has the to a of ATP- and which of a In the of C. J. Mol. Biol. 1995; PubMed Scopus Google Scholar), the are into a and and into four the of within the of the In E. coli PCK, the of the the is and has a of within the with of the this have suggested A. H. J. Mol. Biol. PubMed Scopus Google Scholar) that the of PCK is with other and the first in a the of of the E. coli PCK it is from the and represents an of of the with a of the two an of A. U. H. Biol. PubMed Scopus Google Scholar). of the two is within the it in in the that the two in a with and ATP-dependent PCKs H. E. Biophys. 1995; PubMed Scopus Google M. C. 1994; PubMed Scopus Google Scholar), in enzymes are and to for and the of of to the of The of important for such as PCK, as as a in have also been in J. Mol. Biol. 1980; PubMed Scopus Google Scholar) and J. Mol. Biol. PubMed Scopus Google are of the PCK that with A. U. H. Biol. PubMed Scopus Google Scholar). The or with the of and is a within this with both and groups of the the an to the Mg2+ of is similar to that found with other that the important is the sequence J. Biochem. 1994; PubMed Scopus Google Scholar), which to the Mg2+ and form with two which in turn form part of the Mg2+ from the and groups of and the of the of the the of the PCK is that which with the and other PCK a to of from the sequence are and with the and The forms a in the which a in binding A. U. H. Biol. PubMed Scopus Google Scholar). in turn to the from to the with and the of of this is that when is the enzyme, a with in H. E. Biophys. 1993; PubMed Scopus Google Scholar). of binding in E. coli PCK is that it is in a with a of A. U. H. Biol. PubMed Scopus Google is a of the of the in the conversion of oxaloacetate to While has been as an of ATP-dependent PCKs, some it is a with to OAA in and PCKs J. Biol. Chem. Full Text PDF PubMed Google Scholar), while other have with in the low Arch. Biochem. Biophys. PubMed Scopus Google Scholar). In the to the of and for and of ATP-dependent amino acid sequence of ATP-dependent PCKs from E. coli, Trypanosoma and that all of the are this of enzymes A. H. J. Mol. Biol. PubMed Scopus Google Scholar). the of E. coli has been found to in both ATP- and GTP-dependent PCKs (11Linss J. Goldenberg S. Urbina J.A. Amazel L.M. Gene (Amst.). 1993; 136: 69-77Crossref PubMed Scopus (26) Google Scholar, M. J. Bacteriol. 1995; PubMed Google Scholar). The and that are all ATP- and GTP-dependent and that have been to the in E. coli this have suggested A. H. J. Mol. Biol. PubMed Scopus Google Scholar) that the a of the PCK which has both groups of PCKs, as a of Urbina J.A. Biophys. PubMed Scopus Google Scholar). In to the both the and are all ATP-dependent PCKs A. H. J. Mol. Biol. PubMed Scopus Google Scholar). There is in the the the are either or show A. U. H. Biol. PubMed Scopus Google Scholar) of a sequence of ATP-dependent PCKs. are and an the of GTP-dependent PCKs. that a similar in binding to their in the ATP-dependent are with an The GTP-dependent enzymes all to a to OAA as as and to the and ATP- and GTP-dependent the lack of overall sequence homology between the two of PCKs, of sequence of GTP-dependent PCKs in of the with the E. coli enzyme that there are of importance to both groups of The has been as an of this sequence been suggested to a sequence to other ATP- or (11Linss J. Goldenberg S. Urbina J.A. Amazel L.M. Gene (Amst.). 1993; 136: 69-77Crossref PubMed Scopus (26) Google Scholar, G.M. J. Biol. Chem. Full Text PDF PubMed Google Scholar, G.M. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar, Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google Scholar, A. S. J. Biol. Chem. Full Text PDF PubMed Google Scholar). for the in GTP-dependent PCKs is in this sequence some from the to the of the first all of the for with the and are the is both classes of enzyme. with PCK have that and of this enzyme a J.J. J. Scholar), a with this the to the both the of this in E. coli and other ATP-dependent PCKs A. U. H. Biol. PubMed Scopus Google Scholar), as as differences between and J. Biochem. 1994; PubMed Scopus Google Scholar). is that the between the and in all is similar to that found with the ATP-dependent PCKs that in a similar within the for ATP- and GTP-dependent the differences in overall amino acid sequence homology and nucleotide specificity, the similar between ATP- and GTP-dependent PCKs in of both with OAA binding and binding and that in a similar both groups of as as of the of E. coli PCK, a for and in binding and The of some PCKs from either their to or other for either binding or is the for in monomeric PCKs. The of PCKs a to in some such as phosphorylation of the enzymes from S. S. R. P. Guerritore A. Biophys. PubMed Scopus Google Scholar) and R.P. Leegood R.C. 1995; PubMed Scopus Google is the conversion of OAA to of a decarboxylation of OAA to form the of the from or or it is a J. Biol. Chem. Full Text PDF PubMed Google Scholar, P. M.F. PubMed Scopus (29) Google Scholar, PubMed Scopus Google Scholar, PubMed Scopus Google Scholar). the both in of the of the and the with the E. coli enzyme. decarboxylation while the to the of A. U. H. Biol. PubMed Scopus Google Scholar). The of from both ATP-dependent E. J. Chem. 1993; PubMed Scopus Google Scholar) and GTP-dependent J. Biol. Chem. Full Text PDF PubMed Google Scholar) PCKs in the or decarboxylation has been suggested The that and is the enzyme M. J. Biol. Chem. Full Text PDF PubMed Google Scholar, 1992; PubMed Scopus Google into the decarboxylation from of the of E. coli PCK, in which OAA decarboxylation is is J. Bacteriol. 1995; PubMed Google Scholar). The two of the are in this it a for of the GTP-dependent PCKs also an OAA of M.F. J. Biol. Chem. Full Text PDF PubMed Google all PCKs a in to that which is with the nucleotide for for this a such as PubMed Scopus Google Scholar, G.M. PubMed Scopus (26) Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar) or Urbina J.A. Biophys. PubMed Scopus Google Scholar, PubMed Scopus Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar) in E. coli PCK, (6Goldie H. Sanwal B.D. J. Biol. Chem. 1980; 255: 1399-1405Abstract Full Text PDF PubMed Google Scholar), is in the decarboxylation or a in has also been suggested P. M.F. PubMed Scopus (29) Google Scholar, 1985; 24: PubMed Scopus Google Scholar, PubMed Scopus Google Scholar). such as decarboxylation of OAA in enzymes such as OAA and PCK with OAA and also the during in either the or in Enzyme (Basel). 1992; Scholar). In GTP-dependent PCKs, this the of both and the or of nucleotide either J. Biol. Chem. Full Text PDF PubMed Google Scholar) or 1985; 24: PubMed Scopus Google Scholar, PubMed Scopus Google Scholar) this to for to the and decarboxylation is the of the of the E. coli PCK A. U. H. Biol. PubMed Scopus Google Scholar) and for both ATP-dependent E. Biophys. 1993; PubMed Scopus Google Scholar) and GTP-dependent P. M.F. PubMed Scopus (29) Google Scholar, PubMed Scopus Google Scholar, PubMed Scopus Google Scholar) PCKs a of In E. coli PCK, both which with the of and which and are for of the A. U. H. Biol. PubMed Scopus Google to the for PCKs into a P. M.F. PubMed Scopus (29) Google Scholar, A. J. Biochem. 1980; PubMed Scopus Google Scholar) and PubMed Scopus Google Scholar, 1992; PubMed Scopus Google Scholar, E. Biophys. 1993; PubMed Scopus Google Scholar) with either NTP or OAA first have been the of the enzyme. In E. coli PCK, the is with a pathway of and A. J. Biochem. 1980; PubMed Scopus Google Scholar). of the of E. coli PCK is with an where OAA to the in of from the and the A. U. H. Biol. PubMed Scopus Google Scholar). a also for PCK, as this enzyme a similar in binding H. E. Biophys. 1993; PubMed Scopus Google it that the differences between both groups of PCKs have a similar and with the overall of of of the GTP-dependent PCK to the overall and of binding with the E. coli enzyme. INTRODUCTIONPhosphoenolpyruvate carboxykinase (ATP-oxaloacetate carboxylyase (transphosphorylating), EC 4.1.1.49, or for the GTP- or ITP-dependent enzyme, EC 4.1.1.32; PCK, 1The abbreviations used are: PCKphosphoenolpyruvate carboxykinaseOAAoxaloacetatePEPphosphoenolpyruvateP-loopphosphate-binding loop. also known widely as PEPCK) catalyzes the decarboxylation and mononucleotide-dependent phosphorylation of oxaloacetate to form phosphoenolpyruvate (Scheme 1; M2+ represents Mg2+ or Mn2+).This conversion is the first committed step of gluconeogenesis in Escherichia coli and is part of the gluconeogenic pathway in virtually all organisms. In bacteria, such as E. coli, PCK is utilized during gluconeogenic growth when sugar levels are low (1Goldie H. Sanwal B.D. J. Bacteriol. 1980; 141: 1115-1121Crossref PubMed Google Scholar).PCK is also an important enzyme in the glycolytic pathways of some organisms, such as Ascaris suum (2Christie D.A. Powell J.W. Stables J.N. Watt R.A. Mol. Biochem. Parasitol. 1987; 24: 125-130Crossref PubMed Scopus (12) Google Scholar) and Trypanosoma cruzi (3Cymeryng C. Cazzulo J.J. Cannata J.J. Mol. Biochem. Parasitol. 1995; 73: 91-101Crossref PubMed Scopus (24) Google Scholar), where it forms OAA from PEP, which in turn enters the citric acid cycle. In humans and other mammals, PCK is a central enzyme in carbohydrate metabolism, helping to regulate the blood glucose level. Gluconeogenic tissues, such as kidney and liver, convert lactate and other non-carbohydrate molecules to glucose, which in turn is released into the blood. The importance of PCK to carbohydrate metabolism in humans is such that it has been suggested as a potential drug target in the treatment of non-insulin-dependent diabetes mellitus (4Valera A. Pujol A. Pelegrin M. Bosch F. Proc. Natl. Acad. Sci. U. S. A. 1994; 91: 9151-9154Crossref PubMed Scopus (253) Google Scholar).PCKs have been traditionally classified according to nucleotide specificity, with the ATP-dependent enzymes found in bacteria, yeast, Trypanomastid parasites and plants, and GTP-dependent PCKs in a variety of other eukaryotes and mammals (5Utter M.F. Kolanbrander H.M. Enzyme (Basel). 1972; 6: 117-168Crossref Scopus (252) Google Scholar). There are both important differences and similarities between ATP- and GTP-dependent PCKs. With the exception of bacterial PCKs, which are monomeric (6Goldie H. Sanwal B.D. J. Biol. Chem. 1980; 255: 1399-1405Abstract Full Text PDF PubMed Google Scholar), most enzymes of the ATP-dependent class are multimeric, with two (7Urbina J.A. Arch. Biochem. Biophys. 1987; 258: 186-195Crossref PubMed Scopus (45) Google Scholar), four (8Tortora P. Hanozet G.M. Guerritore A. Anal. Biochem. 1985; 144: 179-185Crossref PubMed Scopus (35) Google Scholar, 9Walker R.P. Trevanion S.J. Leegood R.C. Planta. 1995; 196: 58-63Crossref Scopus (64) Google Scholar), or six (10Finnegan P.M. Burnell J.N. Plant Mol. Biol. 1995; 27: 365-376Crossref PubMed Scopus (27) Google Scholar) subunits per enzyme, while known members of the GTP-dependent class are exclusively monomeric. While enzymes of either the ATP- or GTP-dependent classes show significant (40-80%) amino acid sequence identity within their respective groups (11Linss J. Goldenberg S. Urbina J.A. Amazel L.M. Gene (Amst.). 1993; 136: 69-77Crossref PubMed Scopus (26) Google Scholar, 12Reymond P. Geourjon C. Roux B. Durand R. Fevre M. Gene (Amst.). 1992; 110: 57-63Crossref PubMed Scopus (29) Google Scholar), there is no significant overall sequence homology between the two classes of enzyme. Despite this lack of overall homology, both groups of PCKs contain similar NTP and oxaloacetate binding “consensus in their which similar in binding in this both GTP-dependent and ATP-dependent PCKs have been to C. S. E. Arch. Biochem. Biophys. PubMed Scopus Google Scholar, S. R. H. E. J. Chem. 1993; PubMed Scopus Google Scholar, S. H. E. 1995; PubMed Scopus Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar, PubMed Scopus Google Scholar), E. Biophys. 1987; PubMed Scopus Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar), and J. Biol. Chem. Full Text PDF PubMed Google Scholar, P. C. H. E. J. Chem. PubMed Scopus Google Scholar) or their The differences in nucleotide and between ATP- and GTP-dependent PCKs have to the that potential in Mol. Biochem. Parasitol. 1992; PubMed Scopus Google Scholar) and in Trypanomastid parasites such as cruzi (11Linss J. Goldenberg S. Urbina J.A. Amazel L.M. Gene (Amst.). 1993; 136: 69-77Crossref PubMed Scopus (26) Google from the of E. coli PCK A. H. J. Mol. Biol. PubMed Scopus Google Scholar, A. of E. coli Google Scholar), with A. U. H. Biol. PubMed Scopus Google Scholar), and the for the and of E. coli and other ATP- and GTP-dependent PCKs. also and for the GTP-dependent PCK of GTP-dependent PCK and have been Mol. Biol. 1994; of E. coli of E. coli PCK in M. C. H. J. Mol. Biol. PubMed Scopus Google Scholar) and to the and A. H. J. Mol. Biol. PubMed Scopus Google Scholar). The of the of E. coli PCK A. U. H. Biol. PubMed Scopus Google Scholar). other and E. coli PCK has an The is and of a and a or The two are a of in which the is is such that a central is either an of from the the of E. coli PCK with the C. J. Mol. Biol. 1993; PubMed Scopus Google Scholar) with a significant of overall of the E. coli PCK amino acid sequence with from other ATP- and suggested a most the R. H. H. J. Bacteriol. PubMed Google Scholar). have the of J. Biochem. 1994; PubMed Scopus Google Scholar) for the of within that with this the M. J. PubMed Scopus Google Scholar), the is the PCK the sequence forms a or to ATP- and M. A. Biochem. Sci. Full Text PDF PubMed Scopus Google Scholar). is within the and of the of the that it is in with from a variety of other J. Mol. Biol. PubMed Scopus Google Scholar), U. A. J. PubMed Scopus Google Scholar), and 1992; PubMed Scopus Google Scholar). Despite the within which the is found to for other this Biol. 1992; Scopus Google Scholar) has the to a of ATP- and which of a In the of C. J. Mol. Biol. 1995; PubMed Scopus Google Scholar), the are into a and and into four the of within the of the In E. coli PCK, the of the the is and has a of within the with of the this have suggested A. H. J. Mol. Biol. PubMed Scopus Google Scholar) that the of PCK is with other and the first in a the of of the E. coli PCK it is from the and represents an of of the with a of the two an of A. U. H. Biol. PubMed Scopus Google Scholar). of the two is within the it in in the that the two in a with and ATP-dependent PCKs H. E. Biophys. 1995; PubMed Scopus Google M. C. 1994; PubMed Scopus Google Scholar), in enzymes are and to for and the of of to the of The of important for such as PCK, as as a in have also been in J. Mol. Biol. 1980; PubMed Scopus Google Scholar) and J. Mol. Biol. PubMed Scopus Google are of the PCK that with A. U. H. Biol. PubMed Scopus Google Scholar). The or with the of and is a within this with both and groups of the the an to the Mg2+ of is similar to that found with other that the important is the sequence J. Biochem. 1994; PubMed Scopus Google Scholar), which to the Mg2+ and form with two which in turn form part of the Mg2+ from the and groups of and the of the of the the of the PCK is that which with the and other PCK a to of from the sequence are and with the and The forms a in the which a in binding A. U. H. Biol. PubMed Scopus Google Scholar). in turn to the from to the with and the of of this is that when is the enzyme, a with in H. E. Biophys. 1993; PubMed Scopus Google Scholar). of binding in E. coli PCK is that it is in a with a of A. U. H. Biol. PubMed Scopus Google is a of the of the in the conversion of oxaloacetate to While has been as an of ATP-dependent PCKs, some it is a with to OAA in and PCKs J. Biol. Chem. Full Text PDF PubMed Google Scholar), while other have with in the low Arch. Biochem. Biophys. PubMed Scopus Google Scholar). In the to the of and for and of ATP-dependent amino acid sequence of ATP-dependent PCKs from E. coli, Trypanosoma and that all of the are this of enzymes A. H. J. Mol. Biol. PubMed Scopus Google Scholar). the of E. coli has been found to in both ATP- and GTP-dependent PCKs (11Linss J. Goldenberg S. Urbina J.A. Amazel L.M. Gene (Amst.). 1993; 136: 69-77Crossref PubMed Scopus (26) Google Scholar, M. J. Bacteriol. 1995; PubMed Google Scholar). The and that are all ATP- and GTP-dependent and that have been to the in E. coli this have suggested A. H. J. Mol. Biol. PubMed Scopus Google Scholar) that the a of the PCK which has both groups of PCKs, as a of Urbina J.A. Biophys. PubMed Scopus Google Scholar). In to the both the and are all ATP-dependent PCKs A. H. J. Mol. Biol. PubMed Scopus Google Scholar). There is in the the the are either or show A. U. H. Biol. PubMed Scopus Google Scholar) ATP- and GTP-dependent the lack of overall sequence homology between the two of PCKs, of sequence of GTP-dependent PCKs in of the with the E. coli enzyme that there are of importance to both groups of The has been as an of this sequence been suggested to a sequence to other ATP- or (11Linss J. Goldenberg S. Urbina J.A. Amazel L.M. Gene (Amst.). 1993; 136: 69-77Crossref PubMed Scopus (26) Google Scholar, G.M. J. Biol. Chem. Full Text PDF PubMed Google Scholar, G.M. J. Biol. Chem. 1993; Full Text PDF PubMed Google Scholar, Proc. Natl. Acad. Sci. U. S. A. PubMed Scopus Google Scholar, A. S. J. Biol. Chem. Full Text PDF PubMed Google Scholar). for the in GTP-dependent PCKs is in this sequence some from the to the of the first all of the for with the and are the is both classes of enzyme. with PCK have that and of this enzyme a J.J. J. Scholar), a with this the to the both the of this in E. coli and other ATP-dependent PCKs A. U. H. Biol. PubMed Scopus Google Scholar), as as differences between and J. Biochem. 1994; PubMed Scopus Google Scholar). is that the between the and in all is similar to that found with the ATP-dependent PCKs that in a similar within the for ATP- and GTP-dependent the differences in overall amino acid sequence homology and nucleotide specificity, the similar between ATP- and GTP-dependent PCKs in of both with OAA binding and binding and that in a similar both groups of as as of the of E. coli PCK, a for and in binding and The of some PCKs from either their to or other for either binding or is the for in monomeric PCKs. The of PCKs a to in some such as phosphorylation of the enzymes from S. S. R. P. Guerritore A. Biophys. PubMed Scopus Google Scholar) and R.P. Leegood R.C. 1995; PubMed Scopus Google is the conversion of OAA to of a decarboxylation of OAA to form the of the from or or it is a J. Biol. Chem. Full Text PDF PubMed Google Scholar, P. M.F. PubMed Scopus (29) Google Scholar, PubMed Scopus Google Scholar, PubMed Scopus Google Scholar). the both in of the of the and the with the E. coli enzyme. decarboxylation while the to the of A. U. H. Biol. PubMed Scopus Google Scholar). The of from both ATP-dependent E. J. Chem. 1993; PubMed Scopus Google Scholar) and GTP-dependent J. Biol. Chem. Full Text PDF PubMed Google Scholar) PCKs in the or decarboxylation has been suggested The that and is the enzyme M. J. Biol. Chem. Full Text PDF PubMed Google Scholar, 1992; PubMed Scopus Google into the decarboxylation from of the of E. coli PCK, in which OAA decarboxylation is is J. Bacteriol. 1995; PubMed Google Scholar). The two of the are in this it a for of the GTP-dependent PCKs also an OAA of M.F. J. Biol. Chem. Full Text PDF PubMed Google all PCKs a in to that which is with the nucleotide for for this a such as PubMed Scopus Google Scholar, G.M. PubMed Scopus (26) Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar) or Urbina J.A. Biophys. PubMed Scopus Google Scholar, PubMed Scopus Google Scholar, J. Biol. Chem. Full Text PDF PubMed Google Scholar) in E. coli PCK, (6Goldie H. Sanwal B.D. J. Biol. Chem. 1980; 255: 1399-1405Abstract Full Text PDF PubMed Google Scholar), is in the decarboxylation or a in has also been suggested P. M.F. PubMed Scopus (29) Google Scholar, 1985; 24: PubMed Scopus Google Scholar, PubMed Scopus Google Scholar). such as decarboxylation of OAA in enzymes such as OAA and PCK with OAA and also the during in either the or in Enzyme (Basel). 1992; Scholar). In GTP-dependent PCKs, this the of both and the or of nucleotide either J. Biol. Chem. Full Text PDF PubMed Google Scholar) or 1985; 24: PubMed Scopus Google Scholar, PubMed Scopus Google Scholar) this to for to the and decarboxylation is the of the of the E. coli PCK A. U. H. Biol. PubMed Scopus Google Scholar) and for both ATP-dependent E. Biophys. 1993; PubMed Scopus Google Scholar) and GTP-dependent P. M.F. PubMed Scopus (29) Google Scholar, PubMed Scopus Google Scholar, PubMed Scopus Google Scholar) PCKs a of In E. coli PCK, both which with the of and which and are for of the A. U. H. Biol. PubMed Scopus Google to the for PCKs into a P. M.F. PubMed Scopus (29) Google Scholar, A. J. Biochem. 1980; PubMed Scopus Google Scholar) and PubMed Scopus Google Scholar, 1992; PubMed Scopus Google Scholar, E. Biophys. 1993; PubMed Scopus Google Scholar) with either NTP or OAA first have been the of the enzyme. In E. coli PCK, the is with a pathway of and A. J. Biochem. 1980; PubMed Scopus Google Scholar). of the of E. coli PCK is with an where OAA to the in of from the and the A. U. H. Biol. PubMed Scopus Google Scholar). a also for PCK, as this enzyme a similar in binding H. E. Biophys. 1993; PubMed Scopus Google it that the differences between both groups of PCKs have a similar and with the overall of of of the GTP-dependent PCK